Continuous leakage-resilient certificate-based encryption

Abstract

Encryption schemes are generally considered to be secure in an ideal environment, where the adversary cannot obtain the secret internal state of schemes. However, in the realistic environment, the adversary can gain partial information about decryption private key through various types of side channel attacks. In order to capture these attacks, it is crucial to design encryption schemes which are resilient to leakage. In this article, we first formalize a continuous leakage-resilient security model of certificate-based encryption. In the model, the adversary continuously obtains partial information about the secret states through the continuous leakage attacks. Furthermore, we construct a continuous leakage-resilient certificate-based encryption (CLR-CBE) scheme which is resilient to continuous leakage, and it is secure against adaptive chosen ciphertext attacks under the bilinear Diffie–Hellman inversion (BDHI) hardness assumption. Lastly, we show the bound on leakage and make comparison between proposed and existing schemes in terms of security properties and efficiency.